Bar steadier for seamless tubing mills



June 10, 1958 a. R. GRIFFITHS- 2,337,945

BAR STEADIER FOR SEAMLESS TUBING MILLS 2 Sheets-Sheet 1 Filed July 16.1953 INVENTOR. GEORGE R. GRIFFITHS XMQZM? 434% ATTORNEY June 10, .1958G. R. GRIFFITHS BAR STEADIER FOR SEAMLESS TUBING MILLS 2 Sheets-Sheet 2Filed July 16, 1953 FIG.

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INVENTOR. GEORGE R. GRIFFITHS i OMZJ/.

BAR STEADIER FOR SEAMLESS TUBING MILLS George R. Grifiiths, Gary, Ind.,assignor to United States This invention relates to an improvedbarsteadier for seamless tubing mills and the like.

Seamless tubing mills, such as piercing or rotary expanding mills,conventionally include a mandrel which is supported in the roll pass atthe free end of a rotatable elongated bar. The mandrel is used to workthe inside surface of the tubing :shell; consequently the bar must be ofa length somewhat greater than the maximum shell length. To preventvibration and sagging of the bar it is customary to support it withsteadiers located intermediate its length. Each steadier includes acluster of rolls which normally engage the bar, but which retract toallow the shell to pass. For a more complete disclosure of suchsteadiers and their relation to a mill reference can be made to OlsonPatent No. 1,950,- 929, dated March 13, 1934, or Mohan Patent No.2,306,- 827, dated December 29, 1942.

In some instances it is preferred to employ four-roll steadiers sincethey furnish a more positive grip on a bar than a three-roll steadier.However, previous four-roll steadiers with which I am familiar have notbeen suitable for bars of smaller sizes since the rolls cannot movesufiiciently close together to grip the bar. The minimum diameter barthey can grip is about 2 /2 inches.

An object of the present invention is to provide fourroll :steadierswhich have improved rolls capable of gripping bars of a wider sizerange, that is, capable of gripping bars of small diameter withoutimpairing their ability to grip larger bars. 1

A more specific object is to provide four-roll steadiers whose rollshave mating lands and grooves that enable the rolls to overlap forgripping small diameter bars.

In accomplishin-gthese and other objects of the invention, 1 haveprovided improved details of structure, a preferred form of which isshown in the accompanying drawings, in which:

Figure 1 is a vertical sectional view of a steadier which has rollsconstructed in accordance with my invention, the rolls being retractedfrom the bar;

Figure 2 is a fragmentary vertical section-a1 view showing the rollsengaging a small diameter bar;

Figure 3 is a top plan view on a larger scale of a pair of mating rollsconstructed in accordance with my invention; and

Figure 4 is a top plan view of a pair of rolls constructed in accordancewith a modification of my invention.

Figure 1 shows a pair of supporting beams and a small diameter bar 12 ofa seamless tubing mill. The mill is not otherwise shown since it can beof any standard or desired construction, for example, as shown in theaforementioned Olson or Mohan patents. The'beams 10 carry a barsteadier, which is illustrated as comprising a shaft 13 fixed to the topof the beams, 21 pair of opposed triangularly shaped arms 14 and 15pivotally mounted on said shaft, and double-acting operating cylinders16 and 17 for opening and closing said arms scissors fashion. The twoarms are connected by an equalizer 18. The arm 14 carries upper andlowerrolls 19 and 19a, and the arm 15 carries upper and lower rolls 21)and 29:2, all con- Patented June 10, 1958 structed in accordance with myinvention and hereinafter fully described. The operating mechanismillustrated is merely typical of those used in this type of steadier,and hence is not described in detail and is not to be construed aslimiting the invention.

In accordance with the embodiment of my invention shown in Figure 3, theperiphery of the upper roll 19 on the arm 14 has a central land 21 and apair of grooves 22 and 23 at each end of said land. The periphery of theupper roll 20 on the arm 15 has a central groove 24 and a pair of lands25 and 26 at each end of said groove. The land and grooves on the roll19 are adapted to interfit with the groove and lands on the roll 29.Thus when the arms 14 and 15 are closed to grip the bar 12, as shown inFigure 2, the rolls overlap and can grip a bar of small diameter. Thelower rolls 19a and 20a are shown as of uniform diameter, but it isapparent the lower rolls can have lands and grooves the same as theupper rolls if desired.

In the modification shown in Figure 4 the two upper rolls, designated 30and 31, each have a somewhat larger number of interfitting lands 32 andcorresponding grooves 33. The roll 30' is shown as having four lands 32and five grooves 33, while the roll 31 has five lands and four grooves,but obviously the number can vary.

it is seen that with either embodiment of my invention the arms 14 and15 can close considerably farther than is possible with the usual rollsof uniform outside diameter. I have found in actual practice that barsteadiers which are equipped with my improved rolls can successfullygrip bars of an outside diameter of 1% inches or smaller. At the sametime there is no loss in the effective maximum diameter of the rolls,and consequently they can be used just as successfully to grip largerbars. They furnish the same support to a larger bar as rolls of uniformdiameter equal to that of the lands.

While two embodiments of my invention have been shown and described, itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of the following claim.

I claim:

In a bar steadier which comprises a cluster of four opposed rolls andmeans journalling said rolls on parallel axes and supporting at leasttwo of the rolls for relative movement toward and away from the othertwo, said four rolls when brought together defining a space forreceiving a bar, which space is bounded by a portion of thecircumference of each roll so that the four rolls cooperate to grip thebar, the improvement comprising high cylindrical sections and mating lowsections formed on at least two of said rolls, which two rolls arerelatively movable toward and away from each other, said high and lowsections interfitting when the rolls are brought together enabling thecircumferences of the high sections of two rolls and the circumferencesof the other two rolls to contact a bar of diameter smallerthan thedistance across a space defined by four rolls of uniform diameterequivalent to that of said high sections, the circumferences of saidhigh sections also being adapted to contact a bar of larger diameterwithout the sections interfitting.

References Cited in the file of this patent UNITED STATES PATENTS272,995 Whitney Feb. 27, 1883 1,375,896 Carson Apr. 26, 1921 1,401,131Blackburn Dec. 27, 1921 2,263,744 Smith Nov. 25, 1941 2,306,827 MohanDec. 29, 1942 2,458,110 Sleeman Ian. 4, 1949 2,686,444 Reichl Aug. 17,1954

